1. Field
One or more embodiments of the present invention relate to an apparatus, method and medium compressing and restoring images, and more particularly, to an apparatus, method and medium effectively compressing and restoring edge areas in an image.
2. Description of the Related Art
Existing image compression techniques, such as H.264, JPEG-LS, and the JPEG standards, utilize a basic principle of removing similarities between pixel values constructing an image. The basic principle can be applied to a variety of images, however it cannot be applied to parts of natural images or synthetic images in which little similarity exists between pixel values. In particular, an example of an image in which little similarity exists between pixel values is an edge area of an image. The edge refers to an area whose pixel values have significant differences with respect to values of neighboring pixels.
FIG. 1 illustrates a variety of areas in an image.
Referring to FIG. 1, area 0 demonstrates little change between values of adjacent pixels, while the remaining areas 1, 2, 3, and 4 are areas in which changes between values of adjacent pixels are significant. Areas 1 through 4 are representative edge areas. If existing image compression methods are applied to the edge areas, compression efficiency and picture quality of restored images deteriorate significantly because similarities between pixel values cannot be utilized.